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Date: Thu, 9 Dec 2004 17:44:42 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: [Fwd: [gp AT familiehaase DOT de: sem_* functions in cygwin]]
Message-ID: <20041209164442.GA25246@cygbert.vinschen.de>
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[Catching up on some older mails]

> ----- Forwarded message from "Gerrit P. Haase" -----
> From: "Gerrit P. Haase" 
> To: cygwin ML
> Subject: sem_* functions in cygwin
> Date: Sun, 21 Nov 2004 22:48:20 +0100
> 
> Hi,
> 
> nearly all sem_* functions are available, but sem_unlock is missing,
> was there a problem implementing sem_unlock() or was it just missed
> by accident?
> 
> 
> Gerrit
> ----- End forwarded message -----

I guess you're asking about sem_unlink().  It's not implemented so far
since named POSIX semaphores are implemented using named Windows semaphores. 
The SUSv3 description contains a pretty unfortunate implementation detail:

  Calls to sem_open() to recreate or reconnect to the semaphore refer
  to a new semaphore after sem_unlink() is called.

There's no way I know of, which allows to implement this using named
Windows semaphores.  At least not without adding a lot of annoying
bookkeeping overhead, possibly involving cygserver.


Corinna

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